Confirmation of polychlorinated biphenyl (PCB) distribution in the blood and verification of simple quantitative method for PCBs based on specific congeners.

We measured the concentration of each polychlorinated biphenyl (PCB) congener in whole blood, plasma and blood cells, and investigated the distribution of PCBs in human blood using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The PCB concentrations in plasma and whole blood in terms of lipid concentrations were almost equal, with a correlation coefficient of r=0.972. In the blood, the ratio of PCBs in blood cells to those in plasma was generally about 1:9 and the congener distribution patterns in blood cells and plasma were similar. We performed verification of a simple mass screening method by obtaining information on the main PCB congeners for investigations on human accumulation and exposure. The total concentration of the seven PCB congeners (UNEP-7) proposed to the United Nations Environment Programme (UNEP) by Muir and Morita was about 50% of the total concentration of all PCB congeners, and UNEP-30 was about 80%. The seven main congeners in the blood (MCB-7) showed a value that was about 60%, and MCB-30 showed a value that was about 90%. Determinations with the main congeners in the blood showed a correlation of r=0.990 or more between the main eight congeners (MCB-7 plus #74) and the total PCB concentration for all congeners. The results suggest that, although total PCB concentration can be effectively estimated from the main seven congeners, the main eight congeners would be preferable, and that the use of these congeners in the simple mass screening method would be effective for populations in areas uncontaminated by PCBs.

Perinatal exposure to brominated flame retardants and polychlorinated biphenyls in Japan.

Brominated flame retardants (BFRs) are used to prevent combustion in consumer products. Examples of BFRs are polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and tribromophenol (TBP). These compounds are reported to have adverse effects on human health and endocrine disrupting effects. The purpose of this study was to identify the Japanese perinatal exposure to PBDEs, hydroxylated PBDE metabolites (OH-PBDEs), TBBPA, and TBP compared with polychlorinated biphenyls (PCBs) and hydroxylated PCB metabolites (OH-PCBs). We investigated the concentrations of these compounds in maternal blood, maternal milk, cord blood, and umbilical cords from 16 Japanese mother-infant pairs by HRGC/HRMS. PBDEs were detected in all samples of maternal blood (mean+/-SD; median=25+/-23 pg/g; 18 pg/g wet weight), maternal milk (140+/-220 pg/g; 59 pg/g wet weight), cord blood (4.8+/-6.5 pg/g; 1.6 pg/g wet weight), and umbilical cords (3.1+/-3.1 pg/g; 2.1 pg/g wet weight). The mothers were divided into two groups, a high-concentration group and a low-concentration group. The percentage of BDE-47 showed the greatest difference between the two groups. 6-OH-BDE-47, TBBPA, and TBP were detected in all umbilical cord samples (mean+/-SD; median=8.4+/-8.1 pg/g; 8.0 pg/g, 16+/-5.5 pg/g; 15 pg/g, and 33+/-8.2 pg/g; 32 pg/g wet weight respectively), but not in all maternal blood or cord blood samples. These results indicate that OH-PBDEs, TBBPA, and TBP, in addition to PBDEs, PCBs, and OH-PCBs, pass through the blood-placenta barrier and are retained in the umbilical cord.

Strong correlation between the concentration of dioxins and total PCBs in current Japanese people.

The purpose of this study was to establish an economic and efficient method to screen total PCBs and total dioxins (PCDDs+PCDFs+Co-PCBs) in the highly exposed people in Japan. In this paper, we suggest use of total PCBs in human blood to represent other persistent organic pollutants, especially dioxins. Twenty blood samples were collected from Japanese volunteers. Total PCBs and total dioxins (PCDDs+PCDFs+Co-PCBs) were detected from all twenty blood samples. We carried out detailed analysis of correlation between concentration of total PCBs and each dioxin congener with both measured value and TEQ calculated value. The mean concentration of total PCBs was 250 ng g-fat(-1), and the mean concentration of total dioxins was 37 ng g-fat(-1) or 40 pg TEQ g-fat(-1). Correlations between the total PCBs (ng g-fat(-1)) and the total measured dioxins (ng g-fat(-1)), and between the total PCBs (ng g-fat(-1)) and the total dioxin TEQ calculated value (pg-TEQ g-fat(-1)) were 0.95 and 0.90, respectively. It became clear that the concentrations of total PCBs in human blood is a good indicator of the concentrations of total dioxins in Japan. If a mass screening is conducted on women of reproductive age in order to detect highly exposed women, it is possible that women with the highest contamination may be treated in order to decrease the levels of these chemicals before pregnancy. In conclusion, measurement of total PCBs concentration is useful for exposure assessment of dioxins in human blood.